update Piwik to version 2.16 (fixes #91)

www/analytics/core/Updates/2.0-b13.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * Piwik - Open source web analytics
+ * Piwik - free/libre analytics platform
  *
  * @link http://piwik.org
  * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
@@ -10,12 +10,13 @@ namespace Piwik\Updates;
 
 use Piwik\Filesystem;
 use Piwik\Updates;
+use Piwik\Updater;
 
 /**
  */
 class Updates_2_0_b13 extends Updates
 {
-    public static function update()
+    public function doUpdate(Updater $updater)
     {
         $errors = array();
 
@@ -33,10 +34,9 @@ class Updates_2_0_b13 extends Updates
             if (file_exists($dir)) {
                 $errors[] = "Please delete this directory manually (eg. using your FTP software): $dir \n";
             }
-
         }
-        if(!empty($errors)) {
+        if (!empty($errors)) {
             throw new \Exception("Warnings during the update: <br>" . implode("<br>", $errors));
         }
-   }
+    }
 }